In order to improve the device characteristics of semiconductor devices attempts have been made to reduce the final thickness of semiconductor material. In particular for power semiconductor devices, it is often desired that the semiconductor body of such devices has a thickness which is just sufficient for accommodating the device or circuit.
The manufacturing and handling of thin semiconductor chips and wafers is often complicated since the brittle semiconductor material such as silicon carbide (SiC), once thinned, is prone to breaking. Further, monocrystalline wide band-gap materials are comparatively expensive. To improve the mechanical stability of thin semiconductor material, carrier systems have been developed. For example, a supported wafer may be formed by bonding a monocrystalline SiC substrate to a carrier wafer and subsequent peeling the monocrystalline SiC substrate from the carrier wafer while leaving part of the single-crystal substrate on the carrier wafer. However, unless a comparatively expensive poly-SiC carrier wafer is used, the electrical contact resistance and/or the thermal contact resistance between the monocrystalline SiC substrate and the carrier wafer and/or the electrical resistance and/or the thermal contact resistance of the carrier wafer may interfere with manufacturing. In addition, the high hardness of SiC typically poses a challenge for singulating the supported wafer. Furthermore, forming a contact metallization at the supported side of the monocrystalline SiC substrate may be complicated.
Other carriers often tolerate only moderate processing conditions. For example carriers glued to e.g. SiC-wafers are often limited to temperatures below 350° C. due to the limited thermal stability of the adhesive.
For these and other reasons there is a need for the present invention.